CONTAINER OF THERMOFORMABLE MATERIAL WITH A CLOSING LID INTEGRAL THEREWITH

Abstract: A container of thermoformable material equipped with a closing lid integral therewith comprises a hollow container body (2), a lid (3) and a hinge portion or strip (4) which is integral with the container body (2) on the one side and the lid (3) on the other. The said container has guide means (13) for the lid (3) provided on the container body (2) which slidably engage one edge (15) of the lid (3) close to the said hinge portion or strip (4) when the lid (3) is closed.

Description: CONTAINER OF THERMOFORMABLE MATERIAL WITH A CLOSING LID INTEGRAL THEREWITH This invention relates to a container of thermoformabie material with a closing lid integral therewith, which is particularly indicated for the packaging of food produce such as fruit, vegetables and the like. A container of thermoformabie material having a container body connected to a lid by means of a connecting portion or strip in which two longitudinal recesses acting as a double fold or hinge line are made by thermoforming so that the lid can be placed in a closed position above the container merely by folding over the lid has already been disclosed e.g. in GB-PS 2 185 318 (ISAP S .p.a. ) . Both the lid and the container are equipped with press-stud retaining means to hold the lid in the closed position . In automatic packaging plants, once the container has been filled the lid is generally caused to close by means of a mechanical arm. It may however happen that because of the rigidity of the material of which the interconnecting strip between the container and the lid is made and the inevitable asymmetrical thrust forces applied by the arm to the lid as it closes, the lid is caused to follow an incorrect or crooked closure trajectory with respect to the container body, which may result in defective closure and in some cases failure of the lid to engage with the retention means provided on the container. When this circumstance arises an operator must take action, resulting in additional costs and even a slowing in the operating speed of the packaging plant with a consequent fall in productivity. The principal object of this invention is to eliminate or drastically reduce the abovementioned inconvenience by providing a container with a lid integral therewith which is constructed in such a way as to ensure perfect mating of the lid with the container during the closure stage at all times. Another object of this invention is to provide a container of the abovementioned type which is equipped with great structural stability, which can be stacked stably when filled with produce and which can be manufactured at a competitive cost. This and other objects which will be more apparent below will be accomplished by means of a container of thermoformabie material equipped with a closing lid integral therewith which comprises a hollow container body, a lid and a hinge portion or strip integral with the container body on one side and the lid on the other and characterised in that it has guide means for the lid provided on the container body for slidably engaging one edge of the lid close to the said hinge portion or strip while the lid is being closed. Advantageously the said guide means comprise at least two projections emerging from the container body, at least one of which is intended to engage slidably with the inwardly facing part of the lid edge adjacent to the hinge strip to prevent excessive forward displacement of the lid and the other or others are located so as to engage slidably with the inwardly facing part of at least one edge or side wall of the lid itself in order to avoid lateral displacements of the latter. The invention is further described below with reference to the appended drawings, in which: Figure 1 is a side view in elevation of a container with a lid in a completely open position folded back by 180° with respect to the container body, Figure 2 illustrates a plan view of the container in Figure 1 , Figure 3 shows a detail of Figure 2 on a magnified scale, Figures 4 to 7 are each side views in elevation of the container in Figures 1 and 2 with the lid positioned at various angles of partial closure and in the completely closed position, Figure 8 is a side view in elevation of a variant of the container according to the invention, Figure 9 illustrates a plan view of the container in Figure 8, Figure 10 illustrates a cross-sectional view along the line X-X in Figure 9, Figure 11 is a side view in elevation of another variant of the container according to the invention, and Figure 12 illustrates a plan view of the container in Figure 11. In the appended drawings identical or similar parts or components are identified by means of the same reference numbers. With reference first to container -1 illustrated in Figures 1 to 7, it will be noted that this comprises a container body 2, a lid 3 and a hinge portion or strip 4 which is integral with the rear upper edge 5 of the container body on one side and with the rear edge 6 of the lid on the other. Container body 2 and lid 3 (which is preferably slightly box-shaped) are substantially rectangular in plan with their two corresponding rear corners rounded and the front corners trimmed, indicated by 7 on the container body and 8 on the lid. Each trimmed portion 7 and 8 forms a relatively rigid section of wall on the front of which is provided a portion of male and female retaining means. Typically trimmed corners 7 of the container body have a female connection 9, preferably with an undercut edge, which is designed to engage releasably with a corresponding projection 10 in the lid to form "press-stud" retaining means. Both the container body and the lid have outwardly projecting ribs 11 and 12 in both the base part and the side walls. Ribs 12 extend partly (for example those indicated by 11) in planes parallel to one direction, e.g. the front to back direction, and partly (those indicated by 12) in parallel planes in a direction perpendicular to the former. Also the ribs provided in container body 2 are slightly offset with respect to those provided in lid 3 so that when packed containers 1 are closed they stack together, and the fact that the various ribs of the lid of the container beneath engage the corresponding offset ribs in the container body of the container above prevents mutual displacements between the containers in the stack or pile. At the rear rounded edges of container body 2 there is provided a corresponding arched top projection 13 which follows the curvature of the corner and corresponds to the lower edge of the container body and partly along the edge of the side wall adjacent to it. Preferably each projection 13 has a rearward-facing back or surface configured substantially as an inclined plane (Figure 3). Correspondingly cover 3 has an arched projection 15 at its own rear rounded corners which follows the curvature of the corresponding corner and extends either along the rear edge of the lid or along the side wall adjacent to it, but with a radius of curvature which is slightly greater than that of the corresponding projection 13 on the container body. Advantageously internal wall 16 of each projection 15 is inclined to complement the inclination of the corresponding flat inclined wall of adjacent projection 13. With this arrangement and construction of the parts and components of the container, once lid 3 approaches the container body at a predetermined angle, e.g. approximately 60°, Figure 5, as it is closed, its projections 15 begin to abut against and slidably engage corresponding projections 13 on the container body and ensure a guided rotational movement of the lid towards the container, preventing both uncontrolled forward displacements and lateral displacements of the lid. In this way lid 3 is guided safely to engage accurately with the container body (Figure 7) and in particular projections 10 are inserted accurately into the corresponding receiving seat 9 provided in the container body, as clearly shown in the operating sequence illustrated in Figures 5 to 7. To allow correct bending of hinge portion or strip 4 the latter incorporates two substantially trough-shaped recesses 17 and 18, which constitute lines of weakness and preferential folding for a correct approach by the lid to the container body as it closes. Recesses 17 and 18 are of decreasing depth towards their ends so that they finally become flush with the plane of strip 4, as illustrated in Figure 3. In the variant embodiment illustrated in Figures 8 to 10, hinge portion or strip 4 has an intermediate opening 20 which is used to lighten hinge strip 4 in order to make it yield and fold more easily. This arrangement is particularly advantageous when relatively rigid materials are used to construct the container or if portion 4 has a substantial thickness. Figure 10 in particular shows the trough configuration of a recess 17 which is bevelled down to the plane of portion 4. Figures 11 and 13 illustrate a variant in which projections 13 and 15 are replaced by lateral projections, 13a and 15a respectively, and by rear projections, 13b and 15b respectively. Projections 13a are designed to be slidably engaged by a corresponding projection 15a to guide the lid when it closes so as to prevent lateral slippage thereof, while projections 13b act as engaging members for corresponding projections 15a to ensure that the lid does not advance excessively, but are also guided in a front to rear direction so that they ensure that projections 10 are centred sufficiently accurately on the corresponding receiving seats 9 in the container body. As may be seen, a container having the features described above is capable of effectively accomplishing all the objects specified at the start of this description both in respect of the accuracy of the mating between the lid and the container body during closure and as regards the simplicity of its structure. A container according to this invention allows modifications and variants within the scope of the protection defined by the contents of the following claims. Materials and dimensions may vary according to requirements.

Claims: CLAIMS 1. A container of thermoformabie material equipped with a closing lid integral therewith which incorporates a hollow container body, a lid and a hinge portion or strip integral with the container body on one side and the lid on the other and characterised in that it has guide means for the lid provided on the container body to slidably engage one edge of the lid close to the said hinge portion or strip when the lid is closed. 2. A container according to claim 1 , characterised in that the said guide means comprise at least two projections from the container body, at least one of which is intended to engage slidably with the inwardly facing part of the edge of the lid adjacent to the hinge strip to prevent excessive forward displacement of the lid and the other or others are designed to engage slidably with the inwardly facing part of at least one edge or side wall of the lid to prevent lateral displacements of the latter. 3. A container according to claim 2, characterised in each projection tapers upwards in the form of an inclined plane so as to engage the lid accurately with gradual sliding. 4. A container according to claim 2 or 3, characterised in that the said guide means comprise at least two projections emerging from the lid each designed to contact and engage slidably with a corresponding projection in the container body. 5. A container according to any one of claims 2 to 4, characterised in that both the container body and the lid are provided with two arched projections located at a corresponding corner adjacent to the hinge strip or portion. 6. A container according to any one of the foregoing claims, characterised in that the said hinge strip or portion has a pair of parallel recesses acting as lines of weakness, which have a trough configuration or which are of decreasing depth so as to taper out at the ends of the said hinge portion. 7. A container according to any one of the foregoing claims, characterised in that the said hinge strip or portion has at least one opening or window in order to lighten or weaken it.

Inventors: PADOVANI PIETRO, PADOVANI, PIETRO
Applicants: ISAP OMV GROUP SPA, PADOVANI PIETRO, ISAP OMV GROUP S.P.A., PADOVANI, PIETRO
Application year: 1994
Main classification: B65D43
IPC codes: B65D43